Insulated lightweight cover for pools of water



1968 J. Y. OLDSHUE 3,405,410

INSULATED LIGHTWEIGHT COVER FOR POOLS OF WATER Filed Dec. 13, 1965 39 [[I j/JIXII\\ 1007/ L41. 6

INVENTOR.

JAMES Y. OLDSHUE BY Z g 4 1 FIG. 2 y 7 l: i :i i

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United States Patent 3,405,410 INSULATED LIGHTWEIGHT COVER FOR POOLS OF WATER James Y. Oldshue, 141 Tyringham Road, Rochester, N.Y. 14617 Filed Dec. 13, 1965, Ser. No. 524,633 4 Claims. (Cl. 4-172) ABSTRACT OF THE DISCLOSURE A cover which floats on a pool of fluid consisting of one or more sections, each section consisting of several rigid buoyant pieces flexibly laced together such that each of the pieces may be removed individually from the pool.

This invention provides a cover to insulate a pool of water, for example a swimming pool, from loss of heat, loss of volatile chemicals such as chlorine, and from the intrusion of major amounts of dirt and trash from the atmosphere. The description herein refers often to swimming pools, but the principle of the invention applies just as well to any pool of water where it is desired to accomplish the objectives enumerated here. The examples shown here use a below-ground pool for illustration. The principles apply equally well to above-ground pools, although the relative advantages change somewhat.

At the present time, conventional covers for pools of Water are often of a solid piece or sheet of plastic placed over the pool, and anchored along the top surface of the deck or on the pool coping. They primarily protect the pool against the intrusion of dirt and debris. The placement and removal of these covers is so laborious and timeconsuming that they are used almost entirely for the continuous several weeks ofif-season protection of the pool and not for daily or weekly use as claimed herein.

It is the objective of this invention to provide a practical, lightweight, heat and light-insulating cover which can be placed on the pool and removed by one person, or more of course, either several times daily, daily, weekly, or monthly, so that the advantages of this cover will be available during the season of use of the pool for swimming or other purposes. This cover can be removed and replaced in 5 to minutes or less.

These claims, however, may include other arrangements of cover designs, which while they might be more cumbersome and time-consuming to use than the particular mode of operation here, still would fall within the scope of this disclosure.

This cover can be used for one of three broad objectives:

(a) To reduce loss of heat, loss of volatile chemicals, intrusion of dirt and debris, and algae content of a pool of water that is normally equipped with an auxiliary heat- (b) To be used in such a fashion to collect solar heat during the day and to reduce heat loss during the night so that the pool can be maintained at a comfortable temperature without the use of an auxiliary heater during the extent of the swimming or use season.

(c) To provide all of the advantages of conventional covers during the off-season, with the added advantage of easy installation and removal at the end and beginning of the use season.

Reference to presently available covers will contrast the advantages of this new cover. 7

(a) Present covers are normally a single sheet of plastic, perhaps 0.004 inch to 0.100 inch in thickness, impervious to water, and usually held in place On the pool surface by adding a certain amount of water to the top of them. The amount of water held by the cover fluctuates.

due to evaporation and rainfall. The use of water to hold the cover in place means that the cover must be pumped or siphoned out before it can be removed. Normally, two to four people are required to successfully remove the cover from a 16-foot x 36-foot rectangular pool, and usually requires several hours to accomplish.

(b) The stagnant water held in present covers is conducive to algae growth and to other noxious odors and appearance.

(c) Present covers have no conductive heat transfer insulating value, although they do cut down evaporation heat loss and prevent light from entering the pool. Their difficulty of removal and replacement makes it impractical to use them on a regular basis during the swimming season.

(d) Perforated covers are sometimes used, or it may be attempted not to use water to hold a solid cover in place. Other weighting materials or methods must be used to keep the cover from billowing and blowing during strong winds. In fact, many of the lighter weight solid pool covers billow quite violently during wind storms and often tear and break.

(e) Existing covers are normally fastened, by means of various kinds of weight systems, to the stationary coping, walkway, or deck around the pool. Changes in liquid level in the pool due to inflowing or outflowing leakage can cause present covers to tear and break.

(f) Ice and snow above or below present covers during the winter season also tends to tear and break them- It is the objective of this invention to provide a practical, lightweight, heat insulating and light insulating c-over which can be put in place and removed on a typical home swimming pool by one person in approximately 5 to 15 minutes or less for each operation. The descriptions herein illustrate the general arrangements and dimensions for a typical home swimming pool, which may have a surface area up to 1000 square feet. Two cover sections are illustrated. Any number can be used within the scope of this invention. The sections are shown running parallel to the major axis of the pool. The cover sections can also be used running parallel to the minor axis, or any other arbitrary direction. These principles are just as applicable to larger pools, although multiple cover sections may be used, more than one person may be needed to remove them, and proportionately longer times involved. Of course, proportionately larger advantages in savings will also result.

The particular features of this invention are as follows:

(1) When in place, the cover claimed herein reduces evaporation heat loss, radiation heat loss and conductive heat loss to something on the order of 5 percent or less, compared to a pool of water where the surface is exposed to the atmosphere.

(2) In an actual time test, the entire cover on a 15-foot by 40-foot pool was removed by one person in approximately 5 minutes, and replaced by one person in approximately 5 minutes. This makes the cover practical to put in place during the evening hours and remove it during the daytime hours. It could be removed and replaced several times during the day, although this is probably seldom justified.

It can also be put in place for several days during protracted periods of cool or cloudy weather, or in the case of pool equipment malfunction when the pool must be out of service; or it could be put on during periods of non-use of the pool during the normal swimming season, for example when the owners are away. The heat contained in the pool system can be substantially retained with this cover in place.

(3) This cover is made up of multiple pieces of lightweight heat and light insulating material. When in place, the pieces are fitted in close proximity to each other. The

resulting joints allow rain water to seep through the cover, preventing the collection of water on the top of the cover, which avoids the problems of water collection as on existing pool covers. This does allow fine dust and dirt from the atmosphere and some algae spores to seep into the pool. However, the small amount of fine-sized algae and/ or organic material brought in with the rain can be adequately taken care of by maintaining the chlorine and algaecide residuals in the pool; any inorganic fine material does no real harm to the function of the pool and can be easily removed by vacuuming or brushing for satisfactory appearance when the cover is removed.

The pieces are fitted in close proximity to each other and prevent the entrance to the pool of trash and foreign material such as leaves, branches and other organic material.

(4) In practice, it is most practical to have an auxiliary pool heater so that rapid initial heat-up and rapid response for swimming conditions or other pool use can be maintained. It is possible, however, by placing the cover on the pool between sunset and sunrise, and removing it during the daytime on relatively clear, sunny days, to heat the pool up and maintain it at 75 to 80 F. during the normal swimming season.

(5) When the pool cover is in place for approximately three days, or more, the lack of sunlight will eifectively change the metabolism of any algae in the pool so that it can easily be removed from the pool walls and bottom by brushing or vacuuming. It has proved to be one of the most effective ways for removal of algae, plus saving on algaecide chemicals.

(6) The cover floats on the pool surface and goes up and down with changes in the water level. Straining of the cover with a fixed edge mounting on the deck is eliminated, thus preventing breaking and tearing.

(7) In the winter the insulating value of the cover can be equivalent to 4 feet of ice. Normally ice will not form under the cover described herein during extreme winter conditions in the United States in latitudes as far north as 43. The extension of this principle can be calculated by standard heat transfer techniques.

Many secondary advantages occur by keeping water in the pool during winter months and keeping it free of ice during this time.

(8) During the month of September at 43 latitude north, in the Rochester, New York community, to maintain a heated swimming pool of 600 square feet of area at 80 F. day and night would require an expenditure of about $125 for natural gas. The cost of heating with other fuels could be estimated by accepted techniques. Placing this insulated cover on the pool during the evening hours and during cool, rainy and cloudy periods, and removing it for approximately 8 hours a day on the 12 to 15 average clear days during that month, will reduce this heating bill to $15. In addition, the chlorine consumption would be reduced to approximately percent of its normal value. Algae control and pool cleaning are greatly aided.

This invention consists of the following essential arrangements:

(1) It requires a material that has a lightweight, low thermal conductivity, low light transmission, sufiicient mechanical strength to resist breakage during the handling and have a low hardness and compressive strength so that it will not damage the smooth surface of the walls and bottom of the pool which may be a vinyl plastic liner, paint, plaster or other material.

(2) Expanded, extruded polystyrene as typified by the commercial product Styrofoam is commercially available in sheets to meet these requirements. Other materials which have the following characteristics would also be suitable:

(a) Lightweight, less than 35 pounds per cubic foot. (b) Thermal conductivity of less than 3 B.t.u.-in. per F.

per foot (c) Low light transmission.

(d) Compressive strength of approximately less than 50 p.s.i. at 5% deformation.

(e) Low water absorption. Closed-celled foamed plastics are desirable.

(f) Must be inert to pool chemicals.

(g) Styrofoam is attacked by the ultra-violet rays of the sun, so it must be coated or otherwise protected. Latex paint is suitable.

(3) In order to make this cover readily removable, the pieces of Styrofoam should be of a suitable thickness. One inch is an example of a practical thickness.

(4) Pieces of approximately 2 feet by 8 feet by .1 inch thick are excellent, although pieces down as small as 1 foot by 3 feet by 1 inch would still be acceptable, for the embodiment shown in FIGURES 2, 3, and 4. Smaller sizes are satisfactory for the covers shown in FIGURES 5 and 6.

Tests have shown that pieces of this size floated on a pool will have suflicient flexibility to maintain good interfacial contact with the wave motion generated by high winds, thus utilizing the high interfacial tension between the cover and the water without blowing off. the water surface.

The construction which allows this cover to be operated by one person is described below. The illustration refers to a pool, 11, which is 15 feet wide by 40 feet long, but it should be clear that the principles can be extended to other pool dimensions. It also applies to other shapes, such as square, rectangular, round or irregular. It applies to pools completely above ground, completely below ground and pools with portions both above and below ground level.

FIGURE 1 is a plan view of a typical rectangular pool showing two sections of the cover in place with other features. A phantom view of the stack of pieces is also shown.

FIGURE 2 is a plan view of the individual pieces and their lacing which make up the individual cover sections, showing notches.

FIGURE 3 is a schematic section View of the pieces laced together and a partial stack of pieces intermediate in the removal or replacement of the cover.

FIGURE 4 is an alternate method of lacing showing 1 hole in place of 3 holes.

FIGURE 5 is a schematic sectional view showing a. cover suitable for winding on a continuous roll, illustrating the lacing passing through 1 hole in the piece.

FIGURE 6 is a schematic cross-section showing a method of lacing where the flexible cords are attached by a permanent fastening or adhesive.

In this particular pool, 11, approximately 20 boards, 15, 2 feet by 8 feet by 1 inch, were laced together by a flexible rope 19, or other connecting device. This assembly of pieces is called a section, 13, of the pool cover.

To remove a section, 13, of the pool cover, the removal end piece is lifted off the pool surface and placed on the solid deck, 17, surrounding the pool. The adjacent board is then grasped and placed on top of the first board forming a stack, 25. The lacing is best illustrated schematically in FIGURE 3, and is designed to allow this occurrence.

The pieces in the entire section are subsequently pulled across the water to that end of the pool. The entire section of the cover slides toward the end of the pool where their removal is accomplished due to the connecting flexible cord lacing.

This is illustrated in FIGURE 1 which shows the sections of the pool cover in place. FIGURES 3 and 4 show several methods of lacing to accomplish this stacking, FIGURE 3 shows a partially completed view of the stack and FIGURE 1 shows a phantom view of the stack.

In order to easily grasp succeeding pieces in the cover sections, an approximately 2-inch space, 23, between adjacent pieces is desirable. Under other circumstances, this spacing could be either eliminated, reduced or increased.

As shown in FIGURES 3 and 4, the principle of lacing is that the cord must go from the top of one piece, between the adjacent pieces, to the bottom of the adjacent piece, with suflicient length to allow the spacing and the stacking. A rope, 19, of sufficient strength must be provided. Plastic cord is sufiicient for the lacing material. Any size rope could be be used, but /s-inch diameter has proved satisfactory.

To replace the cover, a length of rope called a leader, 21, is attached to the top piece on the stack, called the replacement end, as shown in FIGURE 1. The operator walks to the end of the pool and by pulling gently on the top piece, it and the remaining pieces slide subsequently into the pool and the entire assemblage is pulled toward the operator. He then walks back to the end which held the initial stack and the one or two pieces that may not come into the pool because of the clearance between the pieces, are pushed in place in close proximity to each other. Notches, 20, are provided so that the pieces will be in substantial contact, and yet allow the laces to go between them. Depending upon the design of the coping, 27, around the deck of the pool, the last piece may either be attached to the section or may be a separate piece to be inserted.

Another important principle in the operation of the cover can be illustrated in replacing the last section of the cover. In order to successfully pull the stacked pieces of the last section of the cover into the pool, a clearance between the cover section in place and the pool container wall surface, 31, must be provided to slide the last pool cover section into the water and pull it down the length of the pool. Any clearance can be used, although 12 inches has proved adequate.

After this section is in place, both sections, 13, are pushed tightly against the wall of the pool, 29, exposing a gap of approximately 1 foot by 40 feet long along one side, 31. Several loose pieces, 33, 1 foot wide for example, and up to 8 feet long, are then placed to cover up the remaining pool surface. These dimensions are typical and not intended to limit the scope of this invention.

If the flexible lacing is continuous, and is to be brought through holes in the pieces making up each portion of the cover, the boards should have an odd number of holes so that the lacing can come from the top of one board, 15, through the joint between the pieces to the bottom of the subsequent board. Three holes, 35, is the preferred arrangement, although 1, 3, 5, 7 or any odd number could be used.

The friction between the cord and the sides of the holes is usually sufficient to prevent relative movement between the lacing and the pieces, but a positive or adhesive fastening could be used. The flexible cords can be attached alternately with an adhesive or fastener rather than passing it through holes.

An alternate construction is to make the cover of pieces, 37, of approximately 3 inches to 8 inches wide. These pieces would then be woven with two laces, 39 and 41, as shown in FIGURES 5 and 6. These sections can be rolled up on a spool or windlass arrangement mounted above or otherwise adjacent to the pool and making a continuous role much like the typical bamboo or reed shades in common use. The Spool or Windlass is not shown.

In summary, this pool cover makes it practical to keep a pool at a comfortable swimming temperature of 78 to 80 F. with an important reduction in heating cost, especially if it is desired to extend pool usage into June, September, May, October or April in the northeastern section of the United States.

A typical example of how this cover would be used in upper New York State, 43 latitude north, in a below ground pool follows:

In April it is probably not practical to heat the pool by alternately removing and replacing the cover during pcriods of sunlight and darkness without the use of an auxiliary heater. With an auxiliary heater, the pool could be initially heated and used for swimming during clear sunlit days and the cover replaced during cool, cloudy or rainy periods.

In May, it would be entirely practical to heat the pool up to 80 F. by judiciously removing and replacing the pool cover. However, an auxiliary heater to initially raise the temperature to the desired level and make short time corrections in pool temperature would be of extreme usefulness.

During the months of June, July and August, the cover could probably be removed completely if an auxiliary heater is available to make up relatively small losses. However, the advantages of algae control, minimized heat loss, keeping debris out of the pool, would be sufficient reason for using the cover on occasion.

On a clear, warm, sunny day at this latitude, during April, May, June, July, August and September, the pool water for an average depth of 6 feet, typically rises about 2 F. Once the pool gets to equilibrium temperature for that climate, which can be calculated from meteorological data, the pool will cool down these 2 at night. In order to raise the pool temperature above the equilibrium temperature, it would require one cycle of a clear day with the pool cover off, and a night with the pool cover on, for each degree it is desired to raise the pool above equilibrium temperature.

It is estimated that to raise the pool temperature from 55 to F. during the month of May would require about 20 days of alternate removal and replacement of the cover.

In above-ground pools, water is often left over the winter period. An insulated cover of this type would help in preventing ice formation.

I claim:

1. A floating cover for a pool of fluid, said cover comprising one or more sections, each of said sections comprising a plurality of substantially rigid weft-type pieces, each of said pieces being buoyant, said pieces being arranged to lie in a side-by-side relationship to each other, and warp-type laces flexibly connecting said pieces together to form said section, said laces passing from the top of each preceding one of said pieces to the bottom of each succeeding one of said pieces adjacent to said preceding one of said pieces. successively to the end of said section.

2. The cover of claim 1 including a lace attached to the last succeeding one of said pieces of said section for drawing said pieces across said fluid.

3. The cover of claim 1 wherein said laces have longitudinal elasticity for drawing said pieces into close proximity with each other when said cover is floating on said fluid and allowing some separation of said pieces when said sections are being removed.

4. The cover of claim 1 wherein said laces are relatively inflexible transversely to their direction so that said pieces are restrained from moving laterally of the laces.

References Cited UNITED STATES PATENTS 748,734 1/1904 Hough 139420 1,645,951 10/1927 Hough 139-420 3,144,665 8/1964 Meyer. 3,091,777 6/1963 Pearlson. 3,052,893 9/1962 McClure.

FOREIGN PATENTS 13,780 6/ 1928 Australia.

LAVERNE D. GEIGER, Primary Examiner.

HENRY ARTIS, Assistant Examiner. 

